research in practice

Systemic Correlations-Part 2

Research associates depression and chronic heart failure with glaucoma.

Mile Brujic, O.D., Crystal Brimer, O.D.

In part two of this two-part series (See “Systemic Correlations – Part 1,” Sept. OM, page 68), we discuss research on the associations between the posterior segment disease glaucoma and systemic conditions.

Specifically, two recent studies shed light on areas of glaucoma care that we must keep in mind.

Supporting research

The recent studies:

1. Glaucoma and chronic heart failure. A recent study shows that patients with chronic heart failure (CHF) were more likely to have low ocular perfusion pressure (OPP) and glaucomatous optic nerve head changes than patients without CHF.1

Specifically, 30 CHF patients and 30 control patients underwent a comprehensive eye exam including: intraocular pressure (IOP) measurements, optic nerve head photography, optic nerve head tomography and standard automated perimetry. OPP was also calculated for both patient groups. It was 45.6mmHg in the CHF group and 54.4mmHg in the control group. These findings are significant, as low OPP means low blood flow to critical ocular tissues, including the optic nerve, and this is one of the leading theories for glaucoma development.

The rim area was slightly lower in the CHF group at 1.41mm2 as compared with the control group, which measured 1.60mm2. The vertical cup-to-disc ratio was significantly greater in the CHF group at 0.51 as compared with the control group at 0.41. Additionally, 10% of patients in the CHF group met the criteria for the glaucoma diagnosis vs. none in the control group.

Here is a right eye fundus photo of a 90 year-old white male who has CHF and moderate glaucomatous optic nerve head changes. Also, note the macular pigment mottling and drusen consistent with age-related macular degeneration.

2. Glaucoma and depression. In a recent study, patients diagnosed with age-related macular degeneration (AMD), Fuch's endothelial dystrophy (FED) or glaucoma had a higher rate of depression than those without a visually limiting eye disease.2 (See “Examining the Senior Patient,” page 22.)

Specifically, 315 patients were recruited for the study: 81 with AMD, 55 with FED, 91 with glaucoma and 88 senior control patients who had good vision. Each group had specific visual entry criteria in order to be eligible for participation in the study group.

Both AMD and FED patients had to have bilateral disease and vision worse than 20/40 in their better-seeing eye.

The glaucoma patients had to have bilateral disease with a visual field mean deviation of -4dB or worse in the eye with more severe glaucoma.

Controls for patients with AMD and FED were those with visual acuities of 20/40 or better in the better-seeing eye.

Controls for the glaucoma patients were those with a visual field mean deviation better than -4dB.

Depressive symptoms in the study were measured by using the Geriatric Depression 15-item scale (see www.psychtoolkit.com/geriatric-depression-scale-short-form-gds-sf.html). All study groups showed a higher rate of depression than the control group.

The most challenging patients, in terms of the glaucoma diagnosis, are those whose aforementioned assessments fall out of the typical range we expect.

As an example, a patient who has IOP measurements of 28mmHg but healthy functioning optic nerves with no signs of glaucomatous damage is a patient we typically classify as having ocular hypertension. So, although this patient is at risk for developing glaucoma, the optic nerve appears to be functioning adequately through its physical architecture and sufficient OPP.

An additional challenge in the glaucoma diagnosis is in better understanding patients who have IOPs in the normal range, but who still progress to glaucoma.3,4 In this instance, there is a disrupted balance between healthy optic nerve head function and sufficient perfusion pressure at an IOP that is seemingly normal.

Low OPP is a risk factor for glaucomatous progression. As OPP is dependent, in part, on the patient's blood pressure, the CHF patient provides a unique challenge that we must be cognizant of when examining this population: Lack of proper cardiac function in CHF patients usually causes a decrease in both systolic and diastolic pressure. This lowers OPP. Therefore, for these patients not diagnosed with glaucoma, be increasingly suspicious of physical changes to the optic nerve head in spite of seemingly normal IOPs. To ensure these patients receive the best care, we suggest you acquire blood pressure measurements. Additionally, those of CHF patients diagnosed with glaucoma may warrant more aggressive IOP goals to prevent further progression.

2. Glaucoma and depression. Depression is an important factor to appreciate, in particular with the glaucoma patient. One study shows that glaucoma patients are more likely to have depression. Another study reveals depressed glaucoma patients were less likely to be persistent with their glaucoma treatment than patients who were not depressed.5

Clinically, you should be cognizant of a patient having depression and the potential for these patients to have less persistence through time with their glaucoma therapy.

Specifically, make a point of educating your depressed patients, in particular, about the longevity of the disease, so they understand the importance of continuing to take their medication(s).

Understanding the role that CHF and depression may have on your patients enhances your ability to identify and successfully manage these patients. OM

DR. BRUJIC IS A PARTNER OF PREMIER VISION GROUP, A FOUR-LOCATION OPTOMETRIC PRACTICE IN NORTHWEST, OHIO. HE HAS A SPECIAL INTEREST IN GLAUCOMA, CONTACT LENSES AND OCULAR DISEASE MANAGEMENT OF THE ANTERIOR SEGMENT. E-MAIL HIM AT BRUJIC@PRODIGY.NET.

DR. BRIMER OWNS CRYSTAL VISION SERVICES, AN OPHTHALMIC EQUIPMENT AND PRACTICE MANAGEMENT CONSULTING COMPANY. SHE PRACTICES IN WILMINGTON, NC AND HAS A SPECIAL INTEREST IN CONTACT LENSES AND DRY EYE MANAGEMENT. E-MAIL HER AT DRBRIMER@CRYS TALVISIONSERVICES.COM, OR SEND COMMENTS TO OPTOM ETRICMANAGEMENT@GMAIL.COM.